Edexcel A-Level Psychology A2 8.1.1 Definitions of Abnormality Topic Practice

Rahul has been finding it difficult to take part in his usual daily activities. He has found it increasingly difficult to leave his house. Rahul feels worried and nervous when meeting new people and he has stopped attending social events with his friends.
A psychiatrist and their trainee have both independently diagnosed Rahul with the same mental health condition using the DSM classification system. Rahul's treatment is helping him return to his usual daily activities.

Describe how Rahul's mental health condition could be defined as a failure to function adequately.